Never did get a chance to try STN for flights to LON, but LHR has been so easy and painless for us (not to mention some very nice non-AA lounges), that I can't imagine STN could be easier.
Cheers.
Easy and painless? Surely you can't be talking about London Heathrow... maybe Little Rock, Arkansas?
For O/D traffic it's tolerable. It's most certainly not easy and painless for connections. Not by a mile.
I'll take any major airport in Europe over LHR - even CDG. Neither are good but at least CDG has the airport staff to go with the atmosphere.
- T